A wide range of lighting devices is known in the art. Some of these lighting devices comprise a string of lighting modules, such as a series of LED (light emitting diode) modules mounted on corresponding printed circuit boards (PCBs), such as flexible printed circuits. Persons skilled in the art will understand that the various LED modules of a string of LED modules are typically connected to each other by means of interconnecting links (“jumpers”).
Additionally, these lighting devices may be sealed for applications in exterior environments. In particular, these devices are typically classified according to the IP (International Protection) classification of the degree of protection, in which the IP code specified in the EN 60529 standard identifies the degree of protection of the casings of the devices against penetration by solid or liquid external agents. For example, lighting devices for exterior use are typically classified in one of the classes IP65 (casing protected against water jets) and IP68 (casing protected against the effects of submersion).
This IP protection can be provided, for example, by means of a potting process in which the device is filled with a solid substance, such as a resin or thermoplastic material. Alternatively, the device can be covered with the protective material (coating) or the protective material can be extruded directly around the device, by a process called co-extrusion. Persons skilled in the art will understand that transparent protective materials, such as silicone, PVC (polyvinyl chloride), polyurethane, and the like are commonly used in the lighting industry.
For example, when producing a lighting device comprising a series of LED modules, it is possible to use a co-extrusion process in which the protective material is applied directly to a string of LED modules having a theoretically infinite length. This string of LED modules is then cut to create strings of LED modules of predetermined lengths, for example strings having lengths varying from 10 to 50 m. Finally, interconnection connectors are applied to the string of LEDs, for example to the first and/or to the last LED module of the string of LEDs.
However, this production process has a number of drawbacks. For example, in order to mount the interconnection connector, the protective material must be partially removed and the interconnection connector must be fixed, by soldering for example, to the printed circuit of one of the LED modules.
In order to avoid this problem, it is possible to apply the protective material only to strings of LEDs which already include interconnection connectors. However, this production process has the drawback that the co-extrusion process is less efficient, because each string of LEDs has to be manufactured independently.